1. Field of the Invention
This invention relates to a slider for slide fasteners and more particularly such a slider which is provided with means for automatically locking the slider relative to the slide fastener.
2. Prior Art
Various automatically lockable sliders are known for use with a standard type of slide fastener having a cooperating pair of coupling element rows mounted on the front side of the fastener, or with a so-called "concealed" type of slide fastener having the coupling element rows mounted on the back side of the fastener such that the coupling elements are concealed or hidden from view when the fastener is fully closed. A typical example of slider for the latter type of slide fasteners is disclosed in Japanese Patent Publication No. 49-18732 in which the slider is provided with a locking member pivotably movable toward and away from a guide channel in the slider body. Since this locking member is exposed directly at the upper surface of the slider body, it is liable to get clogged with foreign matters or receive external stresses leading to malfunctioned slider.
Another type of automatic locking slider proposed in U.S. Pat. No. 2,839,806 has a U-shaped guide bracket along which a pull tab is movable such that the slider can be manipulated optionally from either side of the slide fastener. Since the bracket extends around and outwardly from the slider body, it presents a sort of obstacle to the user particularly when the slider is used only on one side of the fastener.